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E. Rende et al. / Electrochimica Acta 138 (2014) 454–463
Scheme 1.
1.81-1.74 (m, 2H), 1.60-1.52 (m, 2H), 1.30-1.19 (m, 2H); 13C NMR
(100 MHz, CDCl3, ␦): 143.6, 141.3, 138.8, 127.5, 122.9, 122.1, 121.0,
55.7, 32.8, 31.8, 28.3, 26.8, 25.0.
2.2.4. General procedure for the synthesis of monomers
(Fig. 1) (5 mmol), ketone (7 mmol) and propionic acid
(7.2 mmol) were dissolved in 25 mL of toluene. The mixture was
stirred and refluxed for 24 h under argon atmosphere. Toluene was
evaporated and the product was separated by column chromatog-
raphy.
c
a2: 40% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.77 (d, J = 3.5 Hz,
2H), 7.41 (s, 2H), 6.73 (d, J = 2.6 Hz, 2H), 4.71 (t, J = 7.1 Hz, 2H), 3.30
(t, J = 6.7 Hz, 2H), 2.46 (s, 6H), 2.46-2.07 (m, 2H), 1.80-1.73 (m, 2H),
1.49-1.31 (m, 4H); 13C NMR (100 MHz, CDCl3, ␦): 141.0, 139.2,
136.6, 125.8, 125.3, 122.3, 121.2, 55.4, 32.6, 31.4, 28.7, 26.5, 24.7,
14.4.
M1: 80% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.98 (d, J = 3.5 Hz,
2H), 7.52 (s, 2H), 7.27 (d, J = 5.0 Hz, 2H), 7.09-7.06 (m, 2H), 6.71 (d,
J = 3.3 Hz, 2H), 6.57 (d, J = 2.5 Hz, 2H), 6.14 (s, 2H), 4.61 (t, J = 7.0 Hz,
2H), 4.02 (t, J = 7.5 Hz, 2H), 2.35 (s, 6H), 1.98-1.87 (m, 2H), 1.50-1.46
(m, 2H), 1.19-1.12 (m, 4H); 13C NMR (100 MHz, CDCl3, ␦): 141.0,
138.8, 138.6, 131.6, 127.3, 127.0, 125.9, 124.8, 124.5, 124.3, 122.5,
121.7, 109.2, 55.5, 52.3, 29.6, 28.7, 24.8, 24.7, 14.2. MS(m/z): 624
[M + ].
2.2.2. General procedure for the synthesis of b1 and b2
A mixture of a (Fig. 1) (0.87 mmol) and potassium phthalimide
(1.3 mmol) in DMF (30 mL) was stirred for 20 hours. After cooling
to room temperature the mixture was poured into saturated aque-
ous NH4Cl and extracted with ethyl acetate. The organic layer was
washed with water and brine and then dried over MgSO4. After
the removal of solvent, the residue was purified with column chro-
matography to afford the desired product.
M2: 85% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.99 (d, J = 2.9 Hz,
2H), 7.54 (s, 2H), 7.29 (d, J = 5.0 Hz, 2H), 7.18-7.16 (m, 2H), 7.09
(dd, J = 3.7 Hz, J = 5.0, 2H), 6.94-6.92 (m, 4H), 6.22 (s, 2H), 4.62
(t, J = 7.1 Hz, 2H), 4.02 (t, J = 7.6 Hz, 2H), 1.98-1.91 (m, 2H), 1.51-
1.43 (m, 2H), 1.17-1.11 (m, 4H); 13C NMR (100 MHz, CDCl3, ␦):
142.1, 139.9, 134.9, 128.3, 128.1, 127.2, 126.9, 126.0, 125.6, 125.3,
123.6, 122.8, 110.8, 56.6, 44.8, 30.7, 29.7, 25.8, 25.7. MS(m/z): 596
[M + ].
b1: 97% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.98 (d, J = 4.7, 2H),
7.72-7.70 (m, 2H), 7.58-7.56 (m, 2H), 7.50 (s, 2H), 7.27 (d, J = 5.0 Hz,
2H), 7.08 (dd, J = 3.6 Hz, J = 5.0 Hz, 2H), 4.70 (t, J = 7.1 Hz, 2H), 3.58
(t, J = 7.1 Hz, 2H), 2.13-2.06 (m, 2H), 1.64-1.57 (m, 2H), 1.41-1.34
(m, 4H); 13C NMR (100 MHz, CDCl3, ␦): 166.4, 144.3, 138.0, 135.1,
132.2, 131.4, 127.1, 126.5, 126.0, 122.2, 57.6, 38.5, 30.2, 26.4, 25.0,
24.2.
M3: 73% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.77 (d, J = 3.5 Hz,
2H), 7.43 (s, 2H), 7.19-7.18 (m, 2H), 6.96-6.95 (m, 2H), 6.74 (dd,
J = 1.0 Hz, J = 3.5, 2H), 6.23 (s, 2H), 4.61 (t, J = 7.1 Hz, 2H), 4.05
(t, J = 7.6 Hz, 2H), 2.47 (s, 6H), 1.98-1.91 (m, 2H), 1.51-1.44 (m,
2H), 1.18-1.10 (m, 4H); 13C NMR (100 MHz, CDCl3, ␦): 141.0,
139.2, 136.7, 133.8, 127.2, 126.2, 125.9, 125.3, 124.9, 124.2, 122.3,
121.1, 109.8, 55.4, 43.8, 29.6, 28.7, 24.7, 24.6, 14.4. MS(m/z): 624
[M + ].
b2: 90% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.71 (d, J = 4.5, 2H),
7.64-7.60 (m, 2H), 7.56-7.51 (m, 2H), 7.27 (d, J = 5.0 Hz, 2H), 6.64 (d,
J = 5.0 Hz, 2H), 3.95 (t, J = 7.1 Hz, 2H), 3.48 (t, J = 6.9 Hz, 2H), 2.70 (s,
6H), 2.03-2.00 (m, 2H), 1.53-1.50 (m, 2H), 1.29-1.08 (m, 4H); 13C
NMR (100 MHz, CDCl3, ␦): 160.4, 139.8, 138.0, 135.6, 131.8, 131.0,
129.9, 125.1, 124.4, 120.9, 119.9, 58.2, 35.6, 34.3, 29.2, 26.4, 18.9,
13.3.
2.3. Theoretical Details
Geometry optimizations and electronic structure calculations
of the gas-phase monomers were carried out at the DFT level, by
employing the 6-31 + G(d,p) basis set and the hybrid B3LYP [35,36]
functional (Becke 3-parameter exchange functional combined with
the Lee, Yang and Parr correlation functional). The geometry of the
three monomers has been fully optimized with tight convergence
criteria, without symmetry constraints, and a subsequent vibra-
tional frequency calculation confirmed the nature of local minima
of the stationary points. Vertical ionization potentials (VIPs) and
electron affinities (VEAs) have been calculated with the ꢀSCF pro-
cedure, where the self-consistent field (SCF) energies, E(M+) and
E(M−) of the cations and anions were obtained at the equilibrium
geometry of the ground electronic state of the neutral monomers.
gas-phase monomers, are used to simulate the UV-vis spectra. The
TDDFT calculations use the B3LYP functional and the 6-31 + G(d,p)
basis-set. All calculations have been carried out by using the Gaus-
sian09 [37] suite of codes.
2.2.3. General procedure for the synthesis of c1 and c2
b (Fig. 1) (0.86 mmol) in ethanol/hydrazine monohydrate (1:1,
30 mL) solution was stirred for 16 hours under reflux. After removal
of solvent, 10% aqueous KOH solution was added to the residue and
extracted with CHCl3. The organic layer was dried over MgSO4 and
concentrated under reduced pressure to afford the product.
c1: 90% yield. 1H NMR (400 MHz, CDCl3, ␦): 8.00 (d, J = 2.5 Hz,
2H), 7.50 (s, 2H), 7.30 (d, J = 5.1 Hz, 2H), 7.10 (dd, J = 3.6 Hz, J = 5.0,
2H), 4.74 (t, J = 7.1 Hz, 2H), 2.60 (t, J = 6.6 Hz, 2H), 2.13 (b, 2H, NH2),
1.89-1.82 (m, 2H), 1.42-1.27 (m, 6H); 13C NMR (100 MHz, CDCl3, ␦):
142.1, 139.9, 128.0, 126.9, 125.5, 123.6, 122.8, 56.7, 42.0, 33.5, 30.0,
29.7, 26.4.
c2: 85% yield. 1H NMR (400 MHz, CDCl3, ␦): 7.75 (d, J = 2.5 Hz,
2H), 7.28 (d, J = 5.0 Hz, 2H), 6.73 (dd, J = 5.1 Hz, J = 5.0, 2H), 3.82 (t,
J = 7.0 Hz, 2H), 2.65 (t, J = 6.5 Hz, 2H), 2.36 (s, 6H), 2.22 (b, 2H, NH2),
1.91-1.87 (m, 2H), 1.52-1.39 (m, 6H); 13C NMR (100 MHz, CDCl3, ␦):
145.0, 137.9, 135.7, 134.3, 127.5, 124.6, 123.8, 59.1, 42.0, 32.7, 30.3,
29.1, 26.4, 15.5.